Hello,
There are several ways to do this. You can do it in a template, but there has to be a way for the template file to know which posts are special.
Have you considered a special category for those posts? You can still include them in any other categories you want, and it would give you a nice way to do it in your template file.
For example, say you create a new category called 'Special'
In your index.php for example, find where the title is displayed:
<h1><a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title(); ?>"><?php the_title(); ?></a></h1>
Replace that with the following code:
<?php
$special = FALSE;
foreach((get_the_category()) as $category) {
if ($category->cat_name == 'Special') $special = TRUE;
}
?>
<h1 <?php if ($special) echo 'class="special"'; ?>><a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title(); ?>"><?php the_title(); ?></a></h1>
As you can see, the first thing the code does is add a quick check to see if the post is in the category called 'Special'. (It has to loop through all categories, because you will probably have posts in multiple categories)
If it is in the category, it sets $special to TRUE. Then in the code to display the post title, it just adds a check within the H1 tag.
<?php if ($special) echo 'class="special"'; ?>
If it is special, it adds the 'special' class to H1, which you could define in your CSS file like this:
h1.special { }
Of course, you could use that for anything - to add a class to a tag as shown above, or add some completely new code, or use as a conditional:
<?php
if ($special) {
show some code
} else {
show something else
}
?>
etc.. lots of options :)